Vertical alignment type VA-LCD's using liquid crystal compositions having negative dielectric anisotropy (negative Δ∈) can express the black of coal-black, and therefore have an excellent display quality. Thus, as high contrast liquid crystal display devices, VA-LCD's have widely penetrated into the liquid crystal TV-centered market. Furthermore, recently, in addition to the active matrix driving systems that are represented by liquid crystal TV's and the like, even in the passive matrix driving systems that are used as display devices for in-vehicle applications or electric appliance applications, the employment of VA-LCD's is increasing. In regard to the liquid crystal TV applications, in order to realize smooth movie display performance, the gap between glass substrates tends to be narrowed, while the birefringence (Δn) of the liquid crystal material tends to increase. On the other hand, in regard to the in-vehicle display devices, in order to obtain satisfactory contrast even in high time-shared driving, namely high multiplex drive with a large display capacity, a liquid crystal composition having negative Δ∈ is required to have a large Δn that has not been conventionally found, and at the same time, the liquid crystal composition is also required to have a large absolute value of Δ∈ in order to cone with voltage lowering. Many liquid crystal compounds and liquid crystal compositions have been suggested as liquid crystal materials for VA-LCD's; however, in order to increase Δn, it is necessary to increase the content of a liquid crystal compound having a large Δn in the liquid crystal composition, and in order to increase the absolute value of Δ∈, it is necessary to increase the content of a liquid crystal compound having a large absolute value of Δ∈ in the liquid crystal composition. However, when the contents of these compounds are increased, viscosity (η) is deteriorated, and consequently, the response speed is deteriorated.
Liquid crystal compositions which exhibit negative values of Δ∈ and large values of Δn have been hitherto disclosed (Patent Literatures 1 to 4). However, the liquid crystal composition described in Patent Literature 1 contains a liquid crystal compound having positive Δ∈, and the absolute value of Δ∈ is small. Furthermore, the liquid crystal compositions described in Patent Literatures 2 to 4 are such that the absolute value of Δ∈ is large but the value of Δn is not sufficiently large. Also, the liquid crystal compositions have large values of η.
Therefore, there is a demand for a liquid crystal composition which has a large absolute value of Δ∈ and a large value of Δn but a small value of η.